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Wyświetlanie 1-15 z 23
Tytuł:
Design and test of a new high-current electronic current transformer with a Rogowski coil
Autorzy:
Zhang, M.
Li, K.
He, S.
Wang, J.
Powiązania:
https://bibliotekanauki.pl/articles/221051.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Rogowski coil
high-current
electronic current transformers
electrical measurements
Opis:
This paper describes the design and test of a new high-current electronic current transformer based on a Rogowski coil. For better performances, electronic current transformers are used to replace conventional electro-magnetic inductive current transformers based on ferromagnetic cores and windings to measure high-current on the high voltage distribution grids. The design of a new high-current electronic current transformer is described in this paper. The principal schemes of the prototype and partial evaluation results are presented. Through relative tests it is known that the prototype has a wide dynamic range and frequency band, and it can allow high accuracy measurements.
Źródło:
Metrology and Measurement Systems; 2014, 21, 1; 121-132
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A complex current ratio device for the calibration of current transformer test sets.
Autorzy:
Çayci, H.
Powiązania:
https://bibliotekanauki.pl/articles/221001.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
current transformer test set
ratio error
phase displacement
current comparator
compensation
Opis:
A practical method with high accuracy in generation and application of error values for calibration of current transformer test sets is described. A PC-controlled three-phase power source with a standard wattmeter is used for generating the nominal and error test currents while an electronically compensated current comparator is used to provide summation and subtraction of them, precisely. With this method, any ratio error and phase displacement values could be generated automatically and nominal and test currents could be grounded on the test set safely. Because of its high accurate ratio and phase error generating capability, any type of test set regardless of its operating principles could be calibrated.
Źródło:
Metrology and Measurement Systems; 2011, 18, 1; 159-164
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An evaluation method of observable charge trap depth for the PEA method and its complementarity with the Q(t) method
Autorzy:
Ren, Hanwen
Takada, Tatsuo
Tanaka, Yasuhiro
Li, Qingmin
Powiązania:
https://bibliotekanauki.pl/articles/1848995.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
pulsed electroacoustic method
trap depth
current integration charge method
leakage current
Opis:
This paper proposes an evaluation method for the observable trap depth range of space charge when using the pulsed electro-acoustic (PEA) method and its complementarity with the current integration charge (Q(t)) method. Based on the measurement process of the PEA method and the hopping conduction principle of space charge, the relationship between the trap depth and the residence time of charge is analysed. A method to analyse the effect of the measurement speed and the spatial resolution of the PEA system on the observable trap depth is then proposed. Further results show when the single measurement time needs 1 s and the resolution is 10 μm at room temperature, the corresponding trap depth is larger than 0.68 eV. Meanwhile, under high temperature or with voltage applied, the depth can further increase. The combined measurement results of the PEA and Q(t) methods indicate that the former focuses on charge distribution in deep traps, which allows to calculate the distorted electric field. The latter can measure the changing process of the total charge involved in all traps, which is applicable to analysing the leakage current. Therefore, the evaluation of HVDC insulation properties based on the joint application of the two methods is more reliable.
Źródło:
Metrology and Measurement Systems; 2021, 28, 3; 565-580
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An evaluation method of observable charge trap depth for the PEA method and its complementarity with the Q(t) method
Autorzy:
Ren, Hanwen
Takada, Tatsuo
Tanaka, Yasuhiro
Li, Qingmin
Powiązania:
https://bibliotekanauki.pl/articles/1849041.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
pulsed electroacoustic method
trap depth
current integration charge method
leakage current
Opis:
This paper proposes an evaluation method for the observable trap depth range of space charge when using the pulsed electro-acoustic (PEA) method and its complementarity with the current integration charge (Q(t)) method. Based on the measurement process of the PEA method and the hopping conduction principle of space charge, the relationship between the trap depth and the residence time of charge is analysed. A method to analyse the effect of the measurement speed and the spatial resolution of the PEA system on the observable trap depth is then proposed. Further results show when the single measurement time needs 1 s and the resolution is 10 μm at room temperature, the corresponding trap depth is larger than 0.68 eV. Meanwhile, under high temperature or with voltage applied, the depth can further increase. The combined measurement results of the PEA and Q(t) methods indicate that the former focuses on charge distribution in deep traps, which allows to calculate the distorted electric field. The latter can measure the changing process of the total charge involved in all traps, which is applicable to analysing the leakage current. Therefore, the evaluation of HVDC insulation properties based on the joint application of the two methods is more reliable.
Źródło:
Metrology and Measurement Systems; 2021, 28, 3; 565-580
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An evaluation method of observable charge trap depth for the pea method and its complementarity with the Q(t) method
Autorzy:
Ren, Hanwen
Takada, Tatsuo
Tanaka, Yasuhiro
Li, Qingmin
Powiązania:
https://bibliotekanauki.pl/articles/1849058.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
pulsed electroacoustic method
trap depth
current integration charge method
leakage current
Opis:
This paper proposes an evaluation method for the observable trap depth range of space charge when using the pulsed electro-acoustic (PEA) method and its complementarity with the current integration charge (Q(t)) method. Based on the measurement process of the PEA method and the hopping conduction principle of space charge, the relationship between the trap depth and the residence time of charge is analysed. A method to analyse the effect of the measurement speed and the spatial resolution of the PEA system on the observable trap depth is then proposed. Further results show when the single measurement time needs 1 s and the resolution is 10 μm at room temperature, the corresponding trap depth is larger than 0.68 eV. Meanwhile, under high temperature or with voltage applied, the depth can further increase. The combined measurement results of the PEA and Q(t) methods indicate that the former focuses on charge distribution in deep traps, which allows to calculate the distorted electric field. The latter can measure the changing process of the total charge involved in all traps, which is applicable to analysing the leakage current. Therefore, the evaluation of HVDC insulation properties based on the joint application of the two methods is more reliable.
Źródło:
Metrology and Measurement Systems; 2021, 28, 3; 565-580
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Programmable Input Mode Instrumentation Amplifier Using Multiple Output Current Conveyors
Autorzy:
Pankiewicz, B.
Powiązania:
https://bibliotekanauki.pl/articles/221277.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
instrumentation amplifier
current conveyor
programmable analogue circuit
Opis:
In this paper a programmable input mode instrumentation amplifier (IA) utilising second generation, multiple output current conveyors and transmission gates is presented. Its main advantage is the ability to choose a voltage or current mode of inputs by setting the voltage of two configuration nodes. The presented IA is prepared as an integrated circuit block to be used alone or as a sub-block in a microcontroller or in a field programmable gate array (FPGA), which shall condition analogue signals to be next converted by an analogue-to-digital converter (ADC). IA is designed in AMS 0.35 µm CMOS technology and the power supply is 3.3 V; the power consumption is approximately 9.1 mW. A linear input range in the voltage mode reaches ± 1.68 V or ± 250 µA in current mode. A passband of the IA is above 11 MHz. The amplifier works in class A, so its current supply is almost constant and does not cause noise disturbing nearby working precision analogue circuits.
Źródło:
Metrology and Measurement Systems; 2017, 24, 1; 79-89
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of Ion Current Measurement to Identification of Combustion Parameters in a Homogeneous Charge Compression Ignition Engine
Autorzy:
Hunicz, J.
Filipek, P.
Sobiesiak, A.
Powiązania:
https://bibliotekanauki.pl/articles/221670.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
HCCI
ion current
heat release rate
combustion control
Opis:
This study examines the application of ion current measurements to the identification of heat release parameters inside the combustion chamber of a homogeneous charge compression ignition (HCCI) engine fuelled with gasoline. HCCI combustion was achieved with the use of exhaust gas trapping. Combustion parameters derived from the in-cylinder pressure and ion current measurements were compared and analysed. Ion current measurements were accomplished using the existing spark plug and a dedicated electronic circuit. The experiments were performed at a variable excess air ratio and a variable amount of trapped residuals. The results showed a good correlation between peak values of the ion current and heat release rate, except for the cases where a fuel-rich mixture was burnt. The computed ion current integral over the volume of the combustion chamber showed a good agreement with the heat released in the combustion chamber, however this parameter was found to be affected by the amount of trapped residuals. Combustion timing characteristic values computed using heat release and ion current were found to be correlated, however the relationship was not linear.
Źródło:
Metrology and Measurement Systems; 2018, 25, 1; 223-234
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New compensation scheme of magneto-optical current sensor for temperature stability improvement
Autorzy:
Chen, J.
Li, H.
Zhang, M.
Zhang, Y.
Powiązania:
https://bibliotekanauki.pl/articles/221874.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
magneto-optical current sensor
normalization
Verdet constant
birefringence
Opis:
A novel magneto-optical current sensor (MOCS) with two sensing arms is proposed to improve the temperature stability. One of the arms, with a highly stable permanent magnet attached and orthogonal to the other one, is designed to provide a reference that follows the temperature characteristics of the sensing material. By a normalization operation between two arms, the temperature drift is compensated adaptively and a sensing output proportional to the measured current can be reached. A dual-input and dual-output structure is specially designed for the reference sensing arm to demodulate the DC Faraday rotation angle. This scheme compensates simultaneously two main temperature influence factors, the Verdet constant and linear birefringence. Validation tests were carried out and are discussed.
Źródło:
Metrology and Measurement Systems; 2012, 19, 3; 611-616
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adaptive filtering-based current reconstruction in non-contact magnetic sensor array measurement system
Autorzy:
Chen, Yafeng
Huang, Qi
Powiązania:
https://bibliotekanauki.pl/articles/221214.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
current measurement
adaptive filtering
sensor array
gauss white noise
Opis:
The non-contact current measurement method with magnetic sensors has become a subject of research. Unfortunately, magnetic sensors fail to distinguish the interested magnetic field from nearby interference and suffer from gauss white noise due to the intrinsic noise of the sensor and external disturbance. In this paper, a novel adaptive filtering-based current reconstruction method with a magnetic sensor array is proposed. Interference-rejection methods based on two classic algorithms, the least-mean-square (LMS) and recursive-least-square (RLS) algorithms, are compared when used in the parallel structure and regular triangle structure of three-phase system. Consequently, the measurement range of RLS-based algorithm is wider than that of LMS-based algorithm. The results of carried out simulations and experiments show that RLS-based algorithms can measure currents with an error of around 1%. Additionally, the RLS-based algorithm can filter the gauss white noise whose magnitude is within 10% of the linear magnetic field range of the sensor.
Źródło:
Metrology and Measurement Systems; 2019, 26, 4; 697-711
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of Time Warping Algorithms for Rail Vehicle Velocity Estimation in Low Speed Scenarios
Autorzy:
Hensel, S.
Marinov, M. B.
Powiązania:
https://bibliotekanauki.pl/articles/221440.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
velocity estimation
cross-correlation
dynamic programming
eddy current sensors
Opis:
Precise measurement of rail vehicle velocities is an essential prerequisite for the implementation of modern train control systems and the improvement of transportation capacity and logistics. Novel eddy current sensor systems make it possible to estimate velocity by using cross-correlation techniques, which show a decline in precision in areas of high accelerations. This is due to signal distortions within the correlation interval. We propose to overcome these problems by employing algorithms from the field of dynamic programming. In this paper we evaluate the application of correlation optimized warping, an enhanced version of dynamic time warping algorithms, and compare it with the classical algorithm for estimating rail vehicle velocities in areas of high accelerations and decelerations.
Źródło:
Metrology and Measurement Systems; 2017, 24, 1; 161-173
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analogue CMOS ASICs in image processing systems
Autorzy:
Jendernalik, W.
Blakiewicz, G.
Handkiewicz, A.
Melosik, M.
Powiązania:
https://bibliotekanauki.pl/articles/221661.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
analog CMOS circuits
early vision processing
switched current filters
Opis:
In this paper a survey of analog application specific integrated circuits (ASICs) for low-level image processing, called vision chips, is presented. Due to the specific requirements, the vision chips are designed using different architectures best suited to their functions. The main types of the vision chip architectures and their properties are presented and characterized on selected examples of prototype integrated circuits (ICs) fabricated in complementary metal oxide semiconductor (CMOS) technologies. While discussing the vision chip realizations the importance of low-cost, low-power solutions is highlighted, which are increasingly being used in intelligent consumer equipment. Thanks to the great development of the automated design environments and fabrication methods, new, so far unknown applications of the vision chips become possible, as for example disposable endoscopy capsules for photographing the human gastrointestinal tract for the purposes of medical diagnosis.
Źródło:
Metrology and Measurement Systems; 2013, 20, 4; 613-622
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of poly-harmonic signals to eddy-current metal detectors and to advanced classification of metals
Autorzy:
Svatoš, J.
Pospíšil, T.
Vedral, J.
Powiązania:
https://bibliotekanauki.pl/articles/220481.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
eddy current
metal detector
polyharmonic signal
signal processing
classification
Opis:
A limited ability to discriminate between different materials is the fundamental problem with all conventional eddy-current-based metal detectors. This paper presents the use, evaluation and classification of nontraditional excitation signals for eddy-current metal detectors to improve their detection and discrimination ability. The presented multi-frequency excitation signals are as follows: a step sweep sine wave, a linear frequency sweep and sin(x)/x signals. All signals are evaluated in the frequency domain. Amplitude and phase spectra and polar graphs of the detector output signal are used for classification and discrimination of the tested objects. Four different classifiers are presented. The classification results obtained with the use of poly-harmonic signals are compared with those obtained with a classical single-tone method. Multi-frequency signals provide more detailed information, due to the response function - the frequency characteristic of a detected object, than standard single-tone methods. Based on the measurements and analysis, a metal object can be better distinguished than when using a single-tone method.
Źródło:
Metrology and Measurement Systems; 2018, 25, 2; 387-402
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Current Fluctuation Measurements of Amperometric Gas Sensors Constructed with Three Different Technology Procedures
Autorzy:
Sedlak, P.
Kubersky, P.
Skarvada, P.
Hamacek, A.
Sedlakova, V.
Majzner, J.
Nespurek, S.
Sikula, J.
Powiązania:
https://bibliotekanauki.pl/articles/220663.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
current fluctuations
noise measurement
amperometric sensor
solid polymer electrolytes
Opis:
Electrochemical amperometric gas sensors represent a well-established and versatile type of devices with unique features: good sensitivity and stability, short response/recovery times, and low power consumption. These sensors operate at room temperature, and therefore have been applied in monitoring air pollutants and detection of toxic and hazardous gases in a number of areas. Some drawbacks of classical electrochemical sensors are overcome by the solid polymer electrolyte (SPE) based on ionic liquids. This work presents evaluation of an SPE-based amperometric sensor from the point of view of current fluctuations. The sensor is based on a novel three-electrode sensor platform with solid polymer electrolytes containing ionic liquid for detection of nitrogen dioxide − a highly toxic gas that is harmful to the environment and presenting a possible threat to human health even at low concentrations. The paper focuses on using noise measurement (electric current fluctuation measurement) for evaluation of electrochemical sensors which were constructed by different fabrication processes: (i) lift-off and drop-casting technology, (ii) screen printing technology on a ceramic substrate and (iii) screen printing on a flexible substrate.
Źródło:
Metrology and Measurement Systems; 2016, 23, 4; 531-543
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Method of earth fault loop impedance measurement without nuisance tripping of RCDs in 3-phase low-voltage circuits
Autorzy:
Czapp, Stanisław
Powiązania:
https://bibliotekanauki.pl/articles/220837.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
power systems
electrical safety
fault current
fault protection
impedance measurement
Opis:
Verification of electrical safety in low-voltage power systems includes the measurement of earth fault loop impedance. This measurement is performed to verify the effectiveness of protection against indirect contact. The widespread classic methods and meters use a relatively high value of the measuring current (5-20) A, so that they are a source of nuisance tripping of residual current devices (RCDs). The meters dedicated to circuits with RCDs usually use an extremely low value of current (lower than 15 mA), which in many cases it is not acceptable in terms of the measurement accuracy. This paper presents a method of earth fault loop impedance measurement in 3-phase circuits, without nuisance tripping of RCDs – the concept of measurement, the meter structure and the experimental validation. The nuisance tripping is avoided in spite of the use of measuring current value many times higher than that of the rated residual current of RCDs. The main advantage of the proposed method is the possibility of creating values of measuring current in a very wide range, what is very important with regard to accuracy of the measurement.
Źródło:
Metrology and Measurement Systems; 2019, 26, 2; 217-227
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An alternating current calibration method for Helmholtz coil constant based on orthogonal calculation principle
Autorzy:
Zhang, Kuankuan
Cao, Mingxing
He, Jian
Gong, Wenjie
Huang, Yunhua
Powiązania:
https://bibliotekanauki.pl/articles/27311758.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
Helmholtz coils constant
alternating current method
induction voltage
orthogonal calculations
Opis:
The Helmholtz coil constant (ℎ) is a crucial standard in magnetic moment measurement devices for permanent magnet materials. To overcome the problem of low accuracy of the direct-current (DC) calibration method, this study used a constant sinusoidal current in the Helmholtz coil and measured the induced voltage of the detection coil with known coil turns and coil area. Subsequently, the ℎ was calculated. The noise signal deduction rate in the induction voltage of the detection coil was greater than 99%, its influence on the induction voltage is less than 0.005%, and the repeatability of the calibration results is 0.003% (1). The results reveal that the alternating current (AC) method and orthogonal calculation (OC) can accurately measure the valid values of the voltage signal under the influence of the spatial stray field during the calibration of ℎ.
Źródło:
Metrology and Measurement Systems; 2023, 30, 3; 549--561
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 23

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